Method of making hydrometers



T. IVHDGLEY, JR.

METHOD OF MAKING HYDROMETERS.

APPLICATION FILED MAR. 31, I916.

1,381,929. Patented June 21,1921.

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UNITED STATES PATENT OFFICE.

THOMAS MIDGLEY J'R OF LANCASTER, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS,TO DELCO-LIGHT COMPANY, OF DAYTON, OHIO, A CORPORATION OF DELAWARE.

METHOD OF MAKING HYDROMETERS.

Specification of Iietters Patent. Patented June 21, 1921.

Application filed March 31, 1916. Serial No. 88,164.

To all whom it may concern:

Be it known that I, THOMAS MIDGLEY, Jr., a citizen of the United States,residing at Lancaster, in the county of Fair-field and State of Ohio,have invented certain new and useful Improvements in Methods of MakingHydrometers, of which the following is a specification.

This invention relates .to the method of making hydrometers, theparticular hydrometer to which this method is applicable is the oneshown in my Patent No. 1,335,253, dated March 20, 1920. The inventionconsists itself in a method whereby these hydrometers may. be cheaplymade and yet be sufficiently accurate for all practical purposes.

In the accompanying sheet of drawing, I have representeddiagrammatically an apparatus by which my method may be carried out anda so a representation of the hydrometer itself. In these drawings:

Figure 1 represents a series of receptacles, which receptacles arethemselves filled or partially filled with a fluid of known specificgravity. For purposes of convenience, I have designated the specificgravity of the various liquids as progressing arithmetically from 1.2 to1.8,

Fig. 2 shows a hydrometer in its completed state, and,

Fig. 3 shows the two sections forming one of the units of thesehydrometers.

My method consists essentially in the provision of standardizinghydrometer units or float members for measuring hydrometers, and theseunits or float members are preferably constructed of sections as isshown in Fig. 3, which sections are designated 1 and 2. The completedunits are designated 3 in Fig. 2, and 1t will be noted that a number ofhydrometer units of different specific gravities may be united by aflexible cord 4. A further description of the use of. the presentinvention in the manner shown in Fig. 2 will be found in my co-pendingapplication, Serial No. 71,171, filed January 10, 1916. These varioussectional units are introduced into a bath of known specific gravity andthose which are then in an unbalanced state are separated from thebalanced ones and the unbalanced sectional units are then successivelyintroduced into the succeeding baths. That is, the sectional unitswhich, when ntroducedinto a bath of given ,specific gravity tend tosink, are separated from the units which tend to float, and these unitswhich tend to sink are then introduced into the succeeding baths until abath having a specific gravlty, such as will cause the units to float,is found. By this arrangement, the various specific gravities of thevarious sectional units may be determined. As an illustration, let it beassumed that a bulk of these sectional units are introduced into thebath designated as having a specific gravity of 1.3. Those sectionalunits which are of a greater density will immediately sink and these maybe said to be in an unbalanced state. These are then removed andintroduced into the succeeding bath desig nated as having a specificgravity of 1.4. A portion of these units will more than likely be foundto have a greater density and these will sink. The unbalanced units arethen successively introduced into the baths of gradually increasingspecific gravities until the specific gravity of all of the units hasbeen determined. If it is then desired to form a hydrometer unit whichwill register a specific gravity of 1.5, the sectional units having aspecific gravity of 1.5 may then be united to form a sphere as indicatedin Fig. 2. These sectional units may be secured together in any suitablemanner, preferably however by being vulcanized together in the propermanner. After this is done, the various combinations of sectional unitswhose mean value will equal 1.5 will-then be united. As an example, theunits having a specific gravity of 1.4 and those having a specificgravity of 1.6 may be united, since the,mean value of their specificgravity is 1.5. Likewise 1.3 and 1.7 may be united and so on.

It will thus appear that I have provided a method whereby hydrometersmay be rapidly and cheaply constructed. It is not intended that thecompleted hydrometer shall be sensitive to a very high degree, but onlyso as to serve all practical purposes such as the testin of milk to knowwhether it has been adu terated or whether it has been skimmed.Likewise, the liquids used in motor vehicles as cooling water, as, forinstance, a 20% solution of alcohol and water, maybe tested to maintainthe correct proportion to prevent its freezing in cold weather.

What I" claim, is:

I l. The method of making hydrometers of the type specified, whichconsists in determining the specific gravity of a plurality of sectionalunits, and then selecting and unit ing certain of said units havingrespectively such specific gravities that each of the completed unitsthus formed thereby shall have,

as a whole, a predetermined specific gravity.

2. The method of making hydrometers of the class described whichconsists in making the hydrometer ing the various sectional units into abath of known specific gravity, separating the balanced units from theunbalanced, succesunits in sections, introduc-' THOMAS MIDGLEY, JR.

Witnesses WALTER E. L. Boon, A. T. PHELPS.

